Furthermore, It's Too Far

When do you use further and farther in a sentence?

In American English, "farther" refers to physical, or literal, distances. Think: far-away city; too far to walk.

Oh my; Emerald City is much farther away than the Munchkins said it was.

All roads lead to Rome, but farther down the road, you'll find Napoli.

"Further" refers to figurative distances—emotional, psychological, conversational, metaphorical. Think: furthermore (farthermore would earn an awk on your essay) or to further a cause (you'd never farther a cause).

I'll have to delve further into this problem.

Peace is further away with each passing day.

Both together now:
I'm not taking this relationship any further; I'm moving farther away than ever.

Thanks for the question.